Twin Base Linkers for Virus Inactivation

ABSTRACT

Functionalized twin base linkers (TBLs) bind to and deactivate viruses by preventing their entry into cells. Functionalization of TBLs allows them to specifically bind to surface proteins of viruses, where they form structures that limit virus entry into cells and prevent viruses from replicating.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 63/010,642, filed 15 Apr. 2020, which is incorporated by reference herein in its entirety.

BACKGROUND

Twin base linkers (TBLs) are biocompatible, biodegradable polymers capable of self-assembly to form rosette nanotubes (RNTs) under physiological conditions. TBLs have been suggested for use in drug delivery due to the presence of a hollow core in RNTs that can accommodate drugs, including hydrophobic drugs (Song, et al. (2011)). TBLs contain covalently linked pairs of guanine-like and cytosine-like bases. Six such pairs form a six-member twin rosette stabilized by 36 hydrogen bonds, and the rosettes stack to form RNTs due to dispersion forces, base stacking interactions, and hydrophobic bonding (Fenniri, et al., 2001). The outer surface of RNTs is hydrophilic, rendering them water soluble. RNTs have been shown to bind to cells, to enhance cell growth, and to have other beneficial actions on cells and tissues.

SUMMARY

The present technology provides targeted twin base linkers (TBLs) to bind to and deactivate viruses by preventing their entry into cells. TBLs are formed from two linked nucleic acid bases and have guanine- and cytosine-like hydrogen bond pairing capability. Monomeric units of TBLs are capable of self-assembly to form supramolecular structures such as hollow nanotubules and other structures.

Functionalization of TBLs in the present technology allows them to specifically bind to surface proteins of viruses, where they form structures that can attach to viruses, limit virus entry into cells, and prevent viruses from replicating.

The technology is further summarized by the following listing of features.

1. An antiviral composition comprising a plurality of functionalized twin base linker (TBL) molecules having the general structure

wherein the twin bases comprise a structure according to Formula 1

wherein L is the linker and comprises carbon, nitrogen, and/or oxygen atoms and has a chain length from about 4 to about 20 atoms;

wherein the peptide moiety contains from about 2 to about 20 L- and/or D-amino acids; and

wherein optionally one or more targeting moieties are covalently linked to the peptide, the targeting moieties capable of specifically binding a surface-accessible protein of a virus, thereby deactivating the virus, or wherein the targeting moieties are absent, and the peptide moiety is capable of specifically binding a surface-accessible protein of a virus, thereby deactivating the virus.

2. The antiviral composition of feature 1, wherein the targeting moieties are present and are selected from the group consisting of antibodies, aptamers, and peptides. 3. The antiviral composition of feature 1 or feature 2, wherein the peptide comprises one or more amino acids that are positively charged at pH 7 and/or one or more amino acids that are negatively charged at pH 7. 4. The antiviral composition of any of the preceding features, wherein the functionalized TBL molecules comprise one or more targeting moieties covalently attached to the peptide moiety, and wherein the one or more targeting moieties are peptides, each peptide having an amino acid sequence that is distinct from that of the peptide moiety. 5. The antiviral composition of any of the preceding features, wherein the functionalized TBL molecules comprise a peptide moiety or a targeting moiety that binds to a virus spike protein, a virus envelope protein, or both. 6. The antiviral composition of feature 5, wherein the peptide moiety or a targeting moiety comprise a peptide selected from the group consisting of SADE (SEQ ID NO:2), SASD (SEQ ID NO:7), SASE (SEQ ID NO:8), and SACD (SEQ ID NO:9). 7. The antiviral composition of any of the preceding features, comprising functionalized TBL molecules in monomeric form. 8. The antiviral composition of any of the preceding features, comprising functionalized TBL molecules in form of a supramolecular assembly. 9. The antiviral composition of any of the preceding features, wherein the peptide moiety or the targeting moieties bind to a protein of SARS-CoV-2 virus. 10. The antiviral composition of feature 9, wherein the peptide moiety or the targeting moieties bind to S protein of SARS-CoV-2 virus. 11. The antiviral composition of feature 10, wherein the peptide moiety or the targeting moieties also bind to E protein of SARS-CoV-2 virus. 12. The antiviral composition of any of the preceding features, wherein the functionalized TBL molecules, or a supramolecular assembly comprising the functionalized TBL molecules, is capable of inhibiting entry of the virus into a mammalian cell. 13. The antiviral composition of any of the preceding features, wherein the functionalized TBL molecules, or a supramolecular assembly comprising the functionalized TBL molecules, is capable of inhibiting death of mammalian cells infected by the virus. 14. The antiviral composition of any of the preceding features, wherein the composition is for use in treating or preventing a viral infection. 15. The antiviral composition of feature 14, wherein the viral infection is caused by a virus selected from the group consisting of a corona virus, SARS-CoV-2, influenza A virus, influenza B virus, an ebola virus, HIV, an adenovirus, a rhinovirus, hepatitis B virus, hepatitis C virus, MERS virus, measles virus, mumps virus, and chickenpox virus. 16. The antiviral composition of feature 14, wherein the composition is for use in treating or preventing two or more viral infections selected from the group consisting of a corona virus, SARS-CoV-2, influenza A virus, influenza B virus, an ebola virus, HIV, an adenovirus, a rhinovirus, hepatitis B virus, hepatitis C virus, MERS virus, measles virus, mumps virus, and chickenpox virus. 17. The antiviral composition of feature 16, wherein the composition is for treating or preventing infection by SARS CoV-2, influenza A virus, influenza B virus, and rhinovirus. 18. A method to aid in treating or preventing a viral infection, the method comprising administering the antiviral composition of any of the preceding features to a subject in need thereof. 19. The method of feature 18, wherein the viral infection is caused by a virus selected from the group consisting of a corona virus, SARS-CoV-2, influenza A virus, influenza B virus, an ebola virus, HIV, adenovirus, a rhinovirus, hepatitis B virus, hepatitis C virus, MERS virus, measles virus, mumps virus, and chickenpox virus. 20. The method of feature 19, wherein the virus is SARS-CoV-2. 21. The method of any of features 18-20, wherein cellular entry of a virus, virus replication, and/or one or more symptoms of the viral infection are reduced or prevented in the subject.

As used herein, the term “about” refers to a range of within plus or minus 10%, 5%, 1%, or 0.5% of the stated value.

As used herein, “consisting essentially of” allows the inclusion of materials or steps that do not materially affect the basic and novel characteristics of the claim. Any recitation herein of the term “comprising”, particularly in a description of components of a composition or in a description of elements of a device, can be exchanged with the alternative expression “consisting of” or “consisting essentially of”.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a twin base G{circumflex over ( )}C motif functionalized with an aminobutyl linker.

FIG. 1B shows a twin base G{circumflex over ( )}C module functionalized with a propionyl linker, which is connected via a peptide bond to a KRSR (SEQ ID NO:1) tetrapeptide. FIG. 1C shows a schematic diagram of a targeted twin base linker motif, in which the peptide moiety is covalently linked through amino acid side chains to targeting moieties.

FIG. 2A shows a prior art model of a rosette structure formed by association of six twin base modules through hydrogen bonds. FIG. 2B shows a prior art model of a nanotubule formed by the stacking of six rosettes such as depicted in FIG. 2A.

FIG. 3 shows a schematic representation of a process of preparing a pseudovirus containing a desired virus spike protein and expressing green fluorescent protein (GFP) or luciferase after infection of target cells.

FIGS. 4A-4C show results of infecting HEK293T cells with a pseudovirus displaying the spike protein of SARS-CoV-2, and expressing GFP in the infected cells. The vertical axis represents arbitrary units of fluorescence, and the horizonal groupings represent pseudovirus concentration (copies/μL) added to the medium. Each grouping of bars shows the concentration of TBL present (left to right: 0, 1 mg/mL, 0.1 mg/mL, 0.01 mg/mL, and 0.001 mg/mL). All amounts of TBL were significantly different (p<0.01) from no TBL. Number of cells was constant for all assays. TBL was functionalized with SADE (SEQ ID NO:2) (SEQ ID NO:2) peptide. Time of incubation of the cells with pseudovirus was 15 min (FIG. 4A), 1 hour (FIG. 4B), or 4 hours (FIG. 4C). All controls (no cells, no pseudovirus) showed no fluorescence.

FIGS. 5A-5C show results of infecting HEK293T cells with a pseudovirus displaying the spike protein of the B117 variant of SARS-CoV-2, and expressing GFP in the infected cells. The vertical axis represents arbitrary units of fluorescence, and the horizonal groupings represent pseudovirus concentration (copies/μL) added to the medium. Each grouping of bars shows the concentration of TBL present (left to right: 0, 1 mg/mL, 0.1 mg/mL, 0.01 mg/mL, and 0.001 mg/mL). All amounts of TBL were significantly different (p<0.01) from no TBL. Number of cells was constant for all assays. TBL was functionalized with SADE (SEQ ID NO:2) peptide. Time of incubation of the cells with pseudovirus was 15 min (FIG. 5A), 1 hour (FIG. 5B), or 4 hours (FIG. 5C).

FIGS. 6A-6C show results of infecting HEK293T cells with a pseudovirus displaying the spike protein of the 501 YV2 variant of SARS-CoV-2, and expressing GFP in the infected cells. The vertical axis represents arbitrary units of fluorescence, and the horizonal groupings represent pseudovirus concentration (copies/μL) added to the medium. Each grouping of bars shows the concentration of TBL present (left to right: 0, 1 mg/mL, 0.1 mg/mL, 0.01 mg/mL, and 0.001 mg/mL). All amounts of TBL were significantly different (p<0.01) from no TBL. Number of cells was constant for all assays. TBL was functionalized with SADE (SEQ ID NO:2) peptide. Time of incubation of the cells with pseudovirus was 15 min (FIG. 6A), 1 hour (FIG. 6B), or 4 hours (FIG. 6C).

FIG. 7 shows results of an experiment to test the ability of functionalized TBL-SADE (SEQ ID NO:2) to protect normal human adult dermal fibroblasts (HDFa from ATCC) from death caused by infection with rhinovirus. Vertical axis shows fluorescence (arbitrary units; Live and Dead Cell Assay by Abcam) indicating dead cells, while the horizonal axis shows the rhinovirus concentration in copies/μL. Concentrations of 0.01 to 1 mg/mL of TBL-SADE inhibited cell death by 96% to 98%.

FIGS. 8A-8B show protection by TBL-SADE of human adult dermal fibroblasts from death by infection with influenza A (FIG. 8A) or influenza B (FIG. 8B) virus. Inhibition was 45% to 55% for influenza A and 42% to 48% for influenza B. Vertical axis shows fluorescence (arbitrary units; Live and Dead Cell Assay by Abcam) indicating dead cells, while the horizonal axis shows the virus concentration in copies/μL

DETAILED DESCRIPTION

The present technology makes use of targeted twin base linkers (TBLs) to bind to and deactivate viruses. TBLs are capable of self-assembly to form supramolecular nanotubules. Such nanomaterials can attach to viruses, limit virus entry into cells, and prevent viruses from replicating.

Viruses are nanoscale structures and, according to the present technology, viruses can be deactivated by the binding of certain other nanoscale structures, including the macromolecular complexes known as twin base linkers. In the present technology, virus entry into target cells is blocked using a nanomaterial that binds to a structure of the virus involved in cellular entry. The entry and infection of a cell by a virus is a multi-step process, the first step of which is the attachment of the virus to receptor molecules at the surface of the target cell. Although nanomaterials can deactivate many viruses, such as those infecting mammalian cells, including human cells, SARS-CoV-2 is discussed below as an example. The technology can be applied to any virus that infects mammalian cells.

Coronaviruses, including the SARS-CoV-2 virus which causes COVID 19, contain round shells of protein molecules that protect the RNA genetic material. Surrounding the shell is a lipid bilayer membrane containing “spike” proteins (S) that contain the site for binding the cellular receptor on the target cell (see, e.g., R. Al-Attabi, et al., 2019). TBL-derived nanomaterials can be targeted to the S protein so that the nanomaterials bind to the region of the virus that is active in promoting cellular entry.

According to the present technology, functionalized TBLs bind a target on the virus, such as the S protein of SARS-CoV-2. While not intending to limit the technology to any particular mechanism, it is believed that the TBLs form a supramolecular structure that wraps around the virus particle, in whole or in part, thereby preventing it from attaching to the target cell of the virus. A functionalized TBL monomer or motif of the present technology can have the general structure depicted in FIG. 1A, for example. The TBL monomer or motif can have a structure as depicted in Formula 1 below.

The twin guanine-like and cytosine-like bases can be attached via a linker, L, such as a diaminobutane moiety, a butyric acid moiety, or other linker, to a peptide. The linker can be a straight or branched chain containing from 2 to 20 carbon atoms; preferably the linker is covalently bound at a first end to a nitrogen atom of the TBL monomer and at a second end is covalently bound via a peptide linkage to the peptide moiety of the TBL. The peptide can be of any desired length, and can itself be used as a targeting moiety capable of binding to the virus binding site, or optionally can serve as a backbone to which is attached one or more optional separate targeting moieties, which can be either identical or non-identical. The targeting moieties can be, for example, peptides, oligopeptides, antibodies, including target-binding fragments thereof, or single chain recombinant antibodies, or aptamers, and can be attached via covalent bonds to amino acid side chains or a terminal NH₂ or COOH group of the peptide moiety, which then serves as a backbone. Alternatively, the backbone can be a nucleic acid (DNA, RNA, or synthetic), a polysaccharide such as dextran, or another polymer. Small peptides are preferred as the targeting moieties, such as peptides containing from 2 to 20 amino acids, or 2-10, 3-12, 4-10, or 4-20 amino acids, such as peptides containing 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acids.

The targeting moieties are selected to provide high affinity binding to the virus. Given that the virus particle contains multiple copies of the virus binding site, the affinity of the functionalized TBL monomers or self-assembled TBL nanostructures containing such monomers can be significantly enhanced by utilizing multiple copies of the targeting moiety, through cooperativity of binding. In addition to high affinity binding provided by one or more targeting moieties attached to the TBL monomers, the twin bases of the TBLs themselves can contribute to high affinity binding through hydrogen bonding between the bases and suitable functional groups on the virus, such as amino acids of the S protein.

For SARS-CoV-2, a preferred binding for TBLs is the receptor binding domain of the S protein, which binds to the natural target of the virus, angiotensin converting enzyme 2 (ACE2). Thus, targeting moieties can be, for example, antibodies or aptamers binding to epitopes within the receptor binding domain of S protein, or peptide fragments of ACE2 that bind to the receptor binding domain of S protein, or glycosylation sites of the S protein. The known amino acid sequence and structure of the S protein, which is described in Kumar et al., 2020, or variants thereof, can be used to select suitable epitopes for targeting. For example, fragments of the receptor binding domain (amino acids 270-510) can be used as epitopes for binding with an antibody or nucleic acid aptamer. Examples of peptides that can be used to bind to and target the novel glycosylation sites (NGTK (SEQ ID NO:3), NFTI (SEQ ID NO:4), NLTT (SEQ ID NO:5), and NTSN (SEQ ID NO:6)) of the S protein of the SARS-CoV-2 virus include: SADE (SEQ ID NO:2), SASD (SEQ ID NO:7), SASE (SEQ ID NO:8), SACD (SEQ ID NO:9), SACE (SEQ ID NO:10), SAPD (SEQ ID NO:11), SAPE (SEQ ID NO:12), SAND (SEQ ID NO:13), SANE (SEQ ID NO:14), SAQD (SEQ ID NO:15), SAQE (SEQ ID NO:16), SVSD (SEQ ID NO:17), SVSE (SEQ ID NO:18), SVCD (SEQ ID NO:19), SVCE (SEQ ID NO:20), SVPD (SEQ ID NO:21), SVPE (SEQ ID NO:22), SVND (SEQ ID NO:23), SVNE (SEQ ID NO:24), SVQD (SEQ ID NO:25), SVQE (SEQ ID NO:26), SLSD (SEQ ID NO:27), SLSE (SEQ ID NO:28), SLCD (SEQ ID NO:29), SLCE (SEQ ID NO:30), SLPD (SEQ ID NO:31), SLPE (SEQ ID NO:32), SLND (SEQ ID NO:33), SLNE (SEQ ID NO:34), SLQD (SEQ ID NO:35), SLDE (SEQ ID NO:36), SMSE (SEQ ID NO:37), SMSD (SEQ ID NO:38), SMCE (SEQ ID NO:39), SMCD (SEQ ID NO:40), SMPD (SEQ ID NO:41), SMPE (SEQ ID NO:42), SMND (SEQ ID NO:43), SMNE (SEQ ID NO:44), SMQD (SEQ ID NO:45), SMQE (SEQ ID NO:46), PASD (SEQ ID NO:47), PASE (SEQ ID NO:48), PACD (SEQ ID NO:49), PACE (SEQ ID NO:50), PAPD (SEQ ID NO:51), PAPE (SEQ ID NO:52), PAND (SEQ ID NO:53), PANE (SEQ ID NO:54), PAQD (SEQ ID NO:55), PAQE (SEQ ID NO:56), PVSD (SEQ ID NO:57), PVSE (SEQ ID NO:58), PVCD (SEQ ID NO:59), PVCE (SEQ ID NO:60), PVPD (SEQ ID NO:61), PVPE (SEQ ID NO:62), PVND (SEQ ID NO:63), PVNE (SEQ ID NO:64), PVQD (SEQ ID NO:65), PVQE (SEQ ID NO:66), PLSD (SEQ ID NO:67), PLSE (SEQ ID NO:68), PLCD (SEQ ID NO:69), PLCE (SEQ ID NO:70), PLPD (SEQ ID NO:71), PLPE (SEQ ID NO:72), PLND (SEQ ID NO:73), PLNE (SEQ ID NO:74), PLQD (SEQ ID NO:75), PLQE (SEQ ID NO:76), PMSD (SEQ ID NO:77), PMSE (SEQ ID NO:78), PMCD (SEQ ID NO:79), PMCE (SEQ ID NO:80), CASD (SEQ ID NO:81), CASE (SEQ ID NO:82), CACD (SEQ ID NO:83), CACE (SEQ ID NO:84), CAPD (SEQ ID NO:85), CAPE (SEQ ID NO:86), CAND (SEQ ID NO:87), CANE (SEQ ID NO:88), CAQD (SEQ ID NO:89), CAQE (SEQ ID NO:90), CVSD (SEQ ID NO:91), CVSE (SEQ ID NO:92), CVCD (SEQ ID NO:93), CVCE (SEQ ID NO:94), CVPD (SEQ ID NO:95), CVPE (SEQ ID NO:96), CVND (SEQ ID NO:97), CVNE (SEQ ID NO:98), CVQD (SEQ ID NO:99), CVQE (SEQ ID NO:100), CLSD (SEQ ID NO:101), CLSE (SEQ ID NO:102), CLCD (SEQ ID NO:103), CLCE (SEQ ID NO:104), CLPD (SEQ ID NO:105), CLPE (SEQ ID NO:106), CLND (SEQ ID NO:107), CLNE (SEQ ID NO:108), CLQD (SEQ ID NO:109), CLQE (SEQ ID NO:110), CMSD (SEQ ID NO:111), CMSE (SEQ ID NO:112), CMCD (SEQ ID NO:113), CMSE (SEQ ID NO:114), CMPD (SEQ ID NO:115), CMPE (SEQ ID NO:116), CMND (SEQ ID NO:117), CMNE (SEQ ID NO:118), CMQD (SEQ ID NO:119), CMQE (SEQ ID NO:120), TASD (SEQ ID NO:121), TASE (SEQ ID NO:122), TACD (SEQ ID NO:123), TACE (SEQ ID NO:124), TAPD (SEQ ID NO:125), TAPE (SEQ ID NO:126), TAND (SEQ ID NO:127), TANE (SEQ ID NO:128), TAQD (SEQ ID NO:129), TAQE (SEQ ID NO:130), TVSD (SEQ ID NO:131), TVSE (SEQ ID NO:132), TVCD (SEQ ID NO:133), TVCE (SEQ ID NO:134), TVPD (SEQ ID NO:135), TVPE (SEQ ID NO:136), TVND (SEQ ID NO:137), TVNE (SEQ ID NO:138), TVQD (SEQ ID NO:139), TVQE (SEQ ID NO:140), TLSD (SEQ ID NO:141), TLSE (SEQ ID NO:142), TLCD (SEQ ID NO:143), TLCE (SEQ ID NO:144), TLPD (SEQ ID NO:145), TLPE (SEQ ID NO:146), TLND (SEQ ID NO:147), TLNE (SEQ ID NO:148), TLQD (SEQ ID NO:149), TLQE (SEQ ID NO:150), TMSD (SEQ ID NO:151), TMSE (SEQ ID NO:152), TMCD (SEQ ID NO:153), TMCE (SEQ ID NO:154), TMPD (SEQ ID NO:155), TMPE (SEQ ID NO:156), TMND (SEQ ID NO:157), TMNE (SEQ ID NO:158), TMQD (SEQ ID NO:159), TMQE (SEQ ID NO:160), QASD (SEQ ID NO:161), QASE (SEQ ID NO:162), QVCD (SEQ ID NO:163), QVCE (SEQ ID NO:164), QVPD (SEQ ID NO:165), QVPE (SEQ ID NO:166), QVND (SEQ ID NO:167), QVNE (SEQ ID NO:168), QVQD (SEQ ID NO:169), QVQE (SEQ ID NO:170), QLSD (SEQ ID NO:171), QLSE (SEQ ID NO:172), QLCD (SEQ ID NO:173), QLCE (SEQ ID NO:174), QLPD (SEQ ID NO:175), QLPE (SEQ ID NO:176), QLND (SEQ ID NO:177), QLNE (SEQ ID NO:178), QLQD (SEQ ID NO:179), QLQE (SEQ ID NO:180), QMSD (SEQ ID NO:181), QMSE (SEQ ID NO:182), QMCD (SEQ ID NO:183), QMCE (SEQ ID NO:184), QMPD (SEQ ID NO:185), QMPE (SEQ ID NO:186), QMND (SEQ ID NO:187), QMNE (SEQ ID NO:188), QMQD (SEQ ID NO:189), QMQE (SEQ ID NO:190). These tetrapeptides, or larger peptides containing them, can be used as targeting moieties.

Similar strategies can be used to select targeting moieties for other viruses. For example, binding of TBLs to the S protein of the MERS virus can be mediated using the targeting moiety peptides MIHS (SEQ ID NO:191), AIHS (SEQ ID NO:192), VIHS (SEQ ID NO:193), IIHS (SEQ ID NO:194), LIHS (SEQ ID NO:195), FIHS (SEQ ID NO:196), YIHS (SEQ ID NO:197), WIHS (SEQ ID NO:198), MAHS (SEQ ID NO:199), MVHS (SEQ ID NO:200), MLHS (SEQ ID NO:201), MMHS (SEQ ID NO:202), MFHS (SEQ ID NO:203), MYHS (SEQ ID NO:204), MWHS (SEQ ID NO:205), AIRS (SEQ ID NO:206), AIRK (SEQ ID NO:207), AIDK (SEQ ID NO:208), AIEK (SEQ ID NO:209), MIHT (SEQ ID NO:210), MIHN (SEQ ID NO:211), and/or MIHQ (SEQ ID NO:212). Binding if TBLs to the neuraminidase of the influenza Type A virus can be obtained using as targeting moiety the peptides ASCS (SEQ ID NO:213), ATCS (SEQ ID NO:214), ANCS (SEQ ID NO:215), AQCS (SEQ ID NO:216), AVCS (SEQ ID NO:217), VSCS (SEQ ID NO:218), VTCS (SEQ ID NO:219), VNCS (SEQ ID NO:220), VQCS (SEQ ID NO:221), WCS (SEQ ID NO:222), ISCS (SEQ ID NO:223), ITCS (SEQ ID NO:224), INCS (SEQ ID NO:225), IQCS (SEQ ID NO:226), IVCS (SEQ ID NO:227), LSCS (SEQ ID NO:228), LTCS (SEQ ID NO:229), LNCS (SEQ ID NO:230), LQCS (SEQ ID NO:231), MSCS (SEQ ID NO:232), MTCS (SEQ ID NO:233), MNCS (SEQ ID NO:234), MQCS (SEQ ID NO:235), MVCS (SEQ ID NO:236), FSCS (SEQ ID NO:237), FTCS (SEQ ID NO:238), FNCS (SEQ ID NO:239), FQCS (SEQ ID NO:240), FVCS (SEQ ID NO:241), YSCS (SEQ ID NO:242), YTCS (SEQ ID NO:243), YNCS (SEQ ID NO:244), YQCS (SEQ ID NO:245), YVCS (SEQ ID NO:246), WSCS (SEQ ID NO:247), WTCS (SEQ ID NO:248), WNCS (SEQ ID NO:249), WQCS (SEQ ID NO:250), and/or WVCS (SEQ ID NO:251). Binding of TBLs to VP1-VP4 in rhinovirus can be obtained using as targeting moiety the peptides MGAQ (SEQ ID NO:252): AGAQ (SEQ ID NO:253), VGAQ (SEQ ID NO:254), IGAQ (SEQ ID NO:255), LGAQ (SEQ ID NO:256), FGAQ (SEQ ID NO:257), YGAQ (SEQ ID NO:258), WGAQ (SEQ ID NO:259), ACAQ (SEQ ID NO:260), VCAQ (SEQ ID NO:261), ICAQ (SEQ ID NO:262), LCAQ (SEQ ID NO:263), MCAQ (SEQ ID NO:264), FCAQ (SEQ ID NO:265), YCAQ (SEQ ID NO:266), WCAQ (SEQ ID NO:267), APAQ (SEQ ID NO:268), VPAQ (SEQ ID NO:269), IPAQ (SEQ ID NO:270), LPAQ (SEQ ID NO:271), FPAQ (SEQ ID NO:272), YPAQ (SEQ ID NO:273), WPAQ (SEQ ID NO:274), AGVQ (SEQ ID NO:275), VGVQ (SEQ ID NO:276), IGVQ (SEQ ID NO:277), LGVQ (SEQ ID NO:278), FGVQ (SEQ ID NO:279), YGVQ (SEQ ID NO:280), WGVQ (SEQ ID NO:281), ACVQ (SEQ ID NO:282), VCVQ (SEQ ID NO:283), ICVQ (SEQ ID NO:284), LCVQ (SEQ ID NO:285), MCVQ (SEQ ID NO:286), FCVQ (SEQ ID NO:287), YCVQ (SEQ ID NO:288), WCVQ (SEQ ID NO:289), APVQ (SEQ ID NO:290), VPVQ (SEQ ID NO:291), IPVQ (SEQ ID NO:292), LPVQ (SEQ ID NO:293), FPVQ (SEQ ID NO:294), YPVQ (SEQ ID NO:295), and/or WPVQ (SEQ ID NO:296).

The TBL monomers and nanostructures of the present technology can also serve to misdirect the targeted virus. For example, either the peptide moiety of the functionalized TBL monomer or one or more of the targeting moieties attached thereto can bind to a selected cellular receptor so as to enhance binding of the virus to receptors that it cannot use to enter cells, or to direct it to cells of the immune system that can destroy it.

The present technology also includes a method to aid in treating or preventing a viral infection. The method includes administering to a subject in need thereof a composition containing a functionalized TBL monomer as described above, and/or a nanostructure formed from one or more types of such functionalized TBL monomers. The subject can be a human or other mammal having or suspected of having or acquiring a viral infection, including COVID-19, SARS, influenza, ebola, rhinovirus, hepatitis B or hepatitis C, MERS, HIV, adenovirus, measles, mumps, chickenpox, or another viral infection. Preferably, the functionalized TBL monomers are administered as an injectable liquid formulation or as an aerosol formulation for direct intrapulmonary administration, wherein the monomers self-assemble within the subject's body to form biodegradable nanostructures with antiviral activity. Alternatively, the monomers can be pre-assembled to form nanostructures prior to administration.

EXAMPLES Example 1. Inhibition of Infection of Mammalian Cells by Pseudovirus Expressing SARS-CoV-2 Spike Protein

Screening studies confirmed binding of TBLs functionalized with the peptide SADE (SEQ ID NO:2) as targeting moiety to the heat-inactivated SARS-CoV-2 spike (S) protein. Binding affinity for SARS-CoV-2 envelope (E) protein by the SADE (SEQ ID NO:2) peptide was also indicated, suggesting that it would serve as a strong targeting moiety, even in the presence of mutations of the S protein. Scrambling of the amino acid sequence of SADE (SEQ ID NO:2) eliminated the binding affinity. Other peptide sequences that were identified as binding SARS-CoV-2 S protein were SASD (SEQ ID NO:7), SASE (SEQ ID NO:8), and SACD (SEQ ID NO:9).

The objective of the present in vitro experiments was to determine the ability of the same TBLs to passivate infection of mammalian cells from a pseudo SARS-CoV-2 virus. The pseudovirus was supplied by Creative Diagnostics. Results of this in vitro study showed that TBLs functionalized with SADE (SEQ ID NO:2) (i.e., the TBS monomer of Formula 1 wherein L=SADE (SEQ ID NO:2) peptide, no further targeting moieties) can passivate the SARS-CoV-2 pseudovirus and inhibit its ability to infect mammalian cells.

A lentiviral SARS-CoV-2 pseudovirus was used for the study. While live SARS-CoV-2 has to be handled under biosafety level 3 conditions, which has hindered the development of vaccines and therapeutics, pseudoviruses are useful virological tools because of their safety and versatility, because the pseudovirus is restricted to a single round of replication and can be handled using BSL-2 containment practices. The pseudovirus expressed GFP in infected cells, allowing infection to be measured with a fluorimeter. The pseudotyped Luciferase/GFP rSARS-CoV-2 displayed antigenically correct spike protein (Wuhan-Hu-1 strain or D614G mutant) pseudotyped on replication-incompetent virus particles that contain a heterologous lentiviral (HIV) core and were capable of a single round of infection. Pseudotyped Luciferase/GFP rSARS-CoV-2 Spike were produced in HEK-293T cells using three separate plasmids (see FIG. 3), and encoded the spike protein, a lentiviral gag polyprotein, and the GFP reporter gene.

HEK293T cells were used for transfection by the pseudovirus. This cell line is constructed by transduction of human angiotensin I converting enzyme 2 (ACE2) into HEK293T cells, followed by stable cell selection. This cell line can be used for in vitro screening and characterization of drug candidates against SARS-CoV-2 because it expresses ACE2 which serves as the host receptor for SARS-CoV-2.

TBLs functionalized with SADE (SEQ ID NO:2) were added at various concentrations (from 0 to 0.001 mg/ml) to selected concentrations of a SARS-CoV-2 pseudovirus (10 to 10⁶ copies/μL) added to HEK293T cells seeded at 10⁴ cells per well. Standard cell culture medium (DMEM+10% FBS) was added to the wells. The TBLs were then allowed to interact with the pseudovirus and cells for periods of time from 15 minutes to 4 hours under standard incubator conditions. After the prescribed time period, the samples were analyzed using a fluorimeter. All experiments were conducted in triplicate and repeated at three different time periods with appropriate controls, including no TBLs, no cells, and no pseudovirus. Differences between fluorescence intensity were assessed using ANOVA and student's t test with p<0.01 considered statistically significant.

Results of this study showed that the TBLs functionalized with SADE (SEQ ID NO:2) significantly inhibited SARS-CoV-2 pseudovirus infection of the mammalian cells at all concentrations and time periods tested (see FIGS. 4A-4C). Inhibition ranged from 64% to 98%. Importantly, a pseudovirus concentration effect was observed;

when more pseudovirus was added to the cultures, more infection was found. However, no strong TBL concentration effect was not observed. All controls confirmed the validity of the experimental system.

Example 2. Inhibition of Infection of Mammalian Cells by Pseudovirus Expressing Variants of SARS-CoV-2 Spike Protein

The experiment described in Example 1 was repeated using a pseudovirus possessing the S protein of the B.1.1.7 variant (see FIGS. 5A-5C) or the 501Y.V2 variant (FIGS. 6A-6C). TBLs were functionalized with SADE (SEQ ID NO:2) (i.e., the TBS monomer of Formula 1 wherein L=SADE (SEQ ID NO:2) peptide, no further targeting moieties).

Inhibition of infection by the B.1.1.7 (UK) variant was dose dependent with respect to the amount of functionalized TBL added, and longer incubation produced somewhat greater inhibition, with the TBL effect being essentially maximum at 1 hour incubation. Inhibition ranged from 76% to 86%.

Inhibition of infection by the 501Y.V2 (South African) variant also showed dose dependency with respect to the amount of functionalized TBL. One hour incubation again produced a maximal effect, and inhibition ranged from producing from 82% to 91% inhibition of infection.

Example 3. Inhibition of Fibroblast Death from Infection by Rhinovirus or Influenza Virus

An experiment similar to that described in Example 1 was performed to test whether TBL functionalized with SADE could protect human dermal fibroblasts from death be infection with rhinovirus, influenza A virus, or influenza B virus. A fluorescent dye was used to indicate dead cells in which fluorescence intensity is proportional to the number of dead cells. The results are shown in FIG. 7 for rhinovirus infection, in FIG. 8A for influenza A infection, and in FIG. 8B for influenza B infection. Death from rhinovirus infection was inhibited by 96% to 98%, while death from influenza virus infection was inhibited by 45% to 55% for influenza A and 42% to 48% for influenza B virus over the range of TBL concentrations tested (0.001 to 1 mg/mL).

A sequence listing is provided as an ASCII text file named “Sequence-Listing-ST25-as-filed-23Jun2021-19815-0693” created on 23 Jun. 2021 and having a size of 45084 bytes. The ASCII text file is hereby incorporated by reference in the application.

REFERENCES

-   R. Al-Attabi, et al., Catalytic electrospun nano-composite membranes     for virus capture and remediation. Separation and Purification     Technology 229, 115806 (2019). -   H. Fenniri, et al., Helical Rosette Nanotubes: Design,     Self-Assembly, and Characterization. J. Am. Chem. Soc. 123,     3854-3855 (2001). -   S. Kumar et al., Structural, glycosylation and antigenic variation     between 2019 novel coronavirus (2019-nCoV) and SARS coronavirus     (SARS-CoV). Virus Dis. doi.org/10.1007/s13337-020.00571-5, 5 Mar.     2020 -   S. Song, et al., Self-assembled rosette nanotubes for incorporating     hydrophobic drugs in physiological environments. Int. J.     Nanomedicine 6, 101-107 (2011). 

1. An antiviral composition comprising a plurality of functionalized twin base linker (TBL) molecules having the general structure

wherein the twin bases comprise a structure according to Formula 1

wherein L is the linker and comprises carbon, nitrogen, and/or oxygen atoms and has a chain length from about 4 to about 20 atoms; wherein the peptide moiety contains from about 2 to about 20 L- and/or D-amino acids; and wherein optionally one or more targeting moieties are covalently linked to the peptide, the targeting moieties capable of specifically binding a surface-accessible protein of a virus, thereby deactivating the virus, or wherein the targeting moieties are absent, and the peptide moiety is capable of specifically binding a surface-accessible protein of a virus, thereby deactivating the virus.
 2. The antiviral composition of claim 1, wherein the targeting moieties are present and are selected from the group consisting of antibodies, aptamers, and peptides.
 3. The antiviral composition of claim 1, wherein the peptide comprises one or more amino acids that are positively charged at pH 7 and/or one or more amino acids that are negatively charged at pH
 7. 4. The antiviral composition of claim 1, wherein the functionalized TBL molecules comprise one or more targeting moieties covalently attached to the peptide moiety, and wherein the one or more targeting moieties are peptides, each peptide having an amino acid sequence that is distinct from that of the peptide moiety.
 5. The antiviral composition of claim 1, wherein the functionalized TBL molecules comprise a peptide moiety or a targeting moiety that binds to a virus spike protein, a virus envelope protein, or both.
 6. The antiviral composition of claim 5, wherein the peptide moiety or a targeting moiety comprise a peptide selected from the group consisting of SADE (SEQ ID NO:2), SASD (SEQ ID NO:7), SASE (SEQ ID NO:8), and SACD (SEQ ID NO:9).
 7. The antiviral composition of claim 1, comprising functionalized TBL molecules in monomeric form.
 8. The antiviral composition of claim 1, comprising functionalized TBL molecules in form of a supramolecular assembly.
 9. The antiviral composition of claim 1, wherein the peptide moiety or the targeting moieties bind to a protein of SARS-CoV-2 virus.
 10. The antiviral composition of claim 9, wherein the peptide moiety or the targeting moieties bind to S protein of SARS-CoV-2 virus.
 11. The antiviral composition of claim 10, wherein the peptide moiety or the targeting moieties also bind to E protein of SARS-CoV-2 virus.
 12. The antiviral composition of claim 1, wherein the functionalized TBL molecules, or a supramolecular assembly comprising the functionalized TBL molecules, is capable of inhibiting entry of the virus into a mammalian cell.
 13. The antiviral composition of claim 1, wherein the functionalized TBL molecules, or a supramolecular assembly comprising the functionalized TBL molecules, is capable of inhibiting death of mammalian cells infected by the virus.
 14. The antiviral composition of claim 1, wherein the composition is for use in treating or preventing a viral infection.
 15. The antiviral composition of claim 14, wherein the viral infection is caused by a virus selected from the group consisting of a corona virus, SARS-CoV-2, influenza A virus, influenza B virus, an ebola virus, HIV, an adenovirus, a rhinovirus, hepatitis B virus, hepatitis C virus, MERS virus, measles virus, mumps virus, and chickenpox virus.
 16. The antiviral composition of claim 14, wherein the composition is for use in treating or preventing two or more viral infections selected from the group consisting of a corona virus, SARS-CoV-2, influenza A virus, influenza B virus, an ebola virus, HIV, an adenovirus, a rhinovirus, hepatitis B virus, hepatitis C virus, MERS virus, measles virus, mumps virus, and chickenpox virus.
 17. The antiviral composition of claim 16, wherein the composition is for treating or preventing infection by SARS CoV-2, influenza A virus, influenza B virus, and rhinovirus.
 18. A method to aid in treating or preventing a viral infection, the method comprising administering the antiviral composition of claim 1 to a subject in need thereof.
 19. The method of claim 18, wherein the viral infection is caused by a virus selected from the group consisting of a corona virus, SARS-CoV-2, influenza A virus, influenza B virus, an ebola virus, HIV, adenovirus, a rhinovirus, hepatitis B virus, hepatitis C virus, MERS virus, measles virus, mumps virus, and chickenpox virus.
 20. The method of claim 19, wherein the virus is SARS-CoV-2.
 21. The method of claim 18, wherein cellular entry of a virus, virus replication, and/or one or more symptoms of the viral infection are reduced or prevented in the subject. 